Key lock Clock
Very simple to use, just click the application icon, set the "Clock screen" on, exit the application and lock the key lock normally. Note that the Clock screen runs in a separate background process, thus any changes made to the settings are effective only after you exit the UI application. This version should work with All S60 3rd/5th edition devices, including Nokia 5800 and N97.
The clock screen lights will not be set on when the keys are locked, since most of the time when device is locked it is not meant to be used, thus to get the lights on you need to press the switcher button (that is used for switching between menu and home screen), also with non-touch devices, the arrow keys can be used for this purpose.
Note that by default the light will go out in 1 second, if longer timeout is needed, then you can set it with settings options between 1 sec and 3599 (1 hour) seconds
You can download the application from the OVI store
This version is available in 38 Languages: English, Albanian, Arabic, Azerbaijan, Bulgarian, Catalan, Chinese (PRC), Chinese (Taiwan), Croatian, Czech, Danish, Dutch, Farsi, Finnish, French, German, Greek, Hebrew, Hungarian, Indonesian, Italian, Korean, Macedonian, Malay, Norwegian, Polish, Portuguese, Romanian, Russian, Serbian, Slovak, Slovenian, Spanish, Swedish, Tamil, Thai, Turkish and Ukrainian